An etched copper or printed conductive circuit pattern on a polymer film base may be referred to as a flexible circuit or flexible printed wiring board. As the name suggests, flexible circuitry can move, bend and twist without damaging the conductors to permit conformity to different shapes and unique package sizes. Originally designed to replace bulky wiring harnesses, flexible circuitry is often the only solution for the miniaturization and movement needed for current, cutting-edge electronic assemblies. Thin, lightweight and ideal for complicated devices, flexible circuit design solutions range from single-sided conductive paths to complex, multilayer three-dimensional packages. Conductive paths can be created through the polymer film by creating metal-plated openings in the polymer layer. These openings can be created by various methods such as laser ablation, plasma-etching and chemical etching. However, if depressions, indentations, or the like, which do not extend all the way through the polymer film, are desired, chemical etching methods are typically preferred for creating these features. Accordingly, there continues to be a need for chemical etchants suitable for controllably etching polymer films.